You would need Spine Professional, due to the data containing PRO features. You would then run Spine and choose 3.6.53, import the data files, save them as a .spine project file. After that you can open the project in 4.1 and export for use with the 4.1 Godot runtimes.
Please note to use the official Spine Runtimes in software that you distribute, you need a Spine Essential or Professional license.